The calculator referenced by Dory36, like the one by T. Rowe Price, does not provide the flexibility that FIRECalc does, in terms of varying the principal amount and withdrawal rate. It also does not account for the way that inflation has historically correlated with stock and bond returns to affect the annual real rate of return on these assets.
It does present an interesting idea as to a withdrawal strategy, but the "catch" is that in certain years of poor market performance, a person would need to curtail their withdrawal amount substantially. This largely defeats the whole point of the retirement planning exercise, which is to identify a fairly constant amount that may be "safely" withdrawn. A person could compensate for this by establishing a separate "rainy day" fund, but it too would need to be invested in some type of assets, and the calculator should ideally account for the performance of that too!
So I still think that FIRECalc is "best" if used with discretion, but these other calculators may provide some ideas as to how FIRECalc could be made even more flexible.
As an adherent of monetarist economic theory, I would add that the common factor that determines the fluctuations in the valuations of different asset classes, and in the inflation rate, is the rate of growth of the money supply. The long-term real (inflation-adjusted)rates of return are determined primarily by the real growth in the output of the economy.
It does present an interesting idea as to a withdrawal strategy, but the "catch" is that in certain years of poor market performance, a person would need to curtail their withdrawal amount substantially. This largely defeats the whole point of the retirement planning exercise, which is to identify a fairly constant amount that may be "safely" withdrawn. A person could compensate for this by establishing a separate "rainy day" fund, but it too would need to be invested in some type of assets, and the calculator should ideally account for the performance of that too!
So I still think that FIRECalc is "best" if used with discretion, but these other calculators may provide some ideas as to how FIRECalc could be made even more flexible.
As an adherent of monetarist economic theory, I would add that the common factor that determines the fluctuations in the valuations of different asset classes, and in the inflation rate, is the rate of growth of the money supply. The long-term real (inflation-adjusted)rates of return are determined primarily by the real growth in the output of the economy.
